An analytical study that explains the existence of a very small region on the mass-radius

No abstract

The similarity theory of stellar structure is used to study the properties of very massive stars when one can neglect all the sources of opacity except for the Thomson scattering. The dimensionless internal structure of such stars is practically independent of the energy generation law. It is shown that the mass-luminosity relation can be approximated by an analytical expression which is virtually universal regarding the chemical composition and energy generation law. A detailed comparison with the Eddington standard model is given. The application of the obtained results to the observations of massive stars is briefly discussed.

No abstract

It is shown that the unusual thermodynamic properties of matter within the region of two-phase coexistence in hybrid stars result in a change of the standard condition for beginning of convection. In particular, the thermal flux transported by convection may be directed towards the stellar center. We discuss favorable circumstances leading to such an effect of "inverse convection" and its possible influence on the thermal evolution of hybrid stars.